Apparently Trump was serious about the idea, even having the GOP poll supporters on the idea. According to Gates, it was Ivanka who talked her father out of the idea.
"What about Ivanka as my VP?" Trump tried to convince his campaign staff in 2016 that his daughter should be his running mate, per Gates book. It was no passing fancy; he brought it up so much the staff polled it twice. @PostRoz @thamburger https://t.co/OlgiPoDyqq
— Peter Baker (@peterbakernyt) September 28, 2020